function soloNum(event) {
    key = (document.all) ? event.keyCode : event.which;
    if(key == 8) return true;
    if (key < 48 || key > 57){
        return false;
    }
    return true;
}

function soloAlfa(nick){
    if(/[^a-zA-Z0-9]/.test(nick)){
        return false;
    }else{
        return true;
    }
}
